Ignition apparatus



Dec. 26, 1933. J DYER I IGNITION APPARATUSF Filed Dec. 11, 1931 Qwww m 50 MM r0 24 piston toward the right for retarding the spark I PatentedDec. 26, 1.933 r PAT-Eur rem 1,941,342 I NI'rroN'APPARATUs ticn'ofDelaware.

Application Decemberll, 1931 -ffSe'ria l No. 580,277

forms; (o1. 123 -117) This invention relatesto ignition apparatusforinternal combustion engines. Q f One of its objects is to control.the'timing of theignition in response to pressure in the engine 5combustion chamber. f Morefparticularly it is an object of the inventionto retardthe spark so as to prevent det'onaation and consequent lo'ssiofpower'while maintaining'the greatest amount of spark advance. consistentwith engine performance.

In order to accomplish this object the present invention providescooperating cylinder and piston members, the former'being connected toan engine cylinder and the latter to the'interrupter support of theignition timer." Movement of the is resisted by a spring which restrainsmovement of the piston from a spark advancing position to a sparkretarding positionuntil the pressure too great spark advance I the"spark is retarded so as to prevent the occurrence-of detonation and lossof power.

invention will'be apparent f'rom the following description, referencebeing had to the accompanying drawing wherein a preferred embodi meritof ionejfer'm of the present. invention is clearly shown. I I I In thedrawings W The figure of the drawing is' a diagram 11115 trating thepresent invention. a I Referring to the-drawing,- the ignition apparatuscomprises a coil 20' having a primary winding 21 and a secondary winding22, The primary 21 is connected by aswitch 23 with a battery 24 groundedat.-25 and is connected by a wire 26 with a terminal 27 of an ignitiontimer. The

terminal 27 is connected by aleaf spring con-.-

ductor 28 with a circuit breaker lever 29 pivoted at 30 upon plate31'which is rotatable about the axis of a shaft 32'which drivestheignition timer cam 33. The cam 33 cooperates with a rubbing block 34attached togetherwith one end of the conductor 28, to the circuitbreaker lever 29. Lever 29 carries a contact 35 cooperating with agrounded contact 36. The normal direction of the rotation of the cam 33isclockwise as indicated by arrow 37. Hence, to advance the spark thecircuit breaker lever plate 31 is rotated counter-clockwise, andclockwise to retard the spark. I

The means for controlling the angular relation 'tain the piston 42substantially in the left-hand in the combustion chamber of theengine'riss substantially to the point of detonation. Thus I when thedetonation would tend to occur. due'to' iFurther objects and advantagesof the 'prese'nt .the spring 43.

between the p1ate31 and the cam 33 responsive to engine combustionpressures comprises a cylinder 40 extending from atirner housing 41 andcooperating with a piston 42 attached to'a rod 43 passing throughathreaded bushing 44 and attached by a pin 45 witha link 46 connected;by pin 47 with the'circuit breaker plate 31.- A spring 48 is locatedbetween'the piston 42 and the bushing 44 and is of such strength as tomainposition shown in the figure until the engine cy1- inder pressurehas increased substantially to a point where detonation would begin tooccur. The cylinder 40 is connected by a pipe 49 with an engine cylinderor combustion chamber 50j The left-handwall of the cylinder 40 providesaseat 51 for a disc valve 52 having notches 53 at its periphery and acentral bleed hole 54. A spring 55 located between the, piston 42 andthe valve 52 tends to retain the valve upon its seat; Since the engineexplosions occur intermittently the piston 42 is subjectedintermittently to increases of pressure. As the pres'sure'fincreases inthe engine cylindervalve 52 'opensto' admit combustion products underpressure to theleft-hand endflof thepiston 42, thus'tending to drive thepiston toward the right; When the combustionpressure decreasesin theenginecylinder, the valve 52is closed by the spring 55. Since thebleedhole 54 in ,the valve'52. is relatively small, the pressureconfined in the cylinder 7 40 is'substantially"retained during theperiod between explosions so that there is relatively little fluctuationof the piston 42. Hence the piston 42 tends to remain in the position.to which it was driven by a preceding explosion in the engine cylinder50. 1' i i As the amount 0 workdone in the engine cylinder increases,the'peak of the combustion pres sure increases; thereby "increasing thepressure upon the piston 42 and still further compressing So long asdetonation does not occur there will be relatively little compression ofspring 43, but when there a tendency for the explosive mixture todetonate, when explod- 1100 ing, the peak of detonation pressure is farin excess of peak pressure before detonation occurs. The peak pressureof detonation although of short duration, is transmitted to the piston42 and that explosion will not detonate because the spark has beenretarded. Then, since the spring 48 is not opposed by a detonatingpressure the forms might be adopted, all coming .within the scope of theclaims which follow.

What is claimed is as follows:

1. Ignition apparatus for internal combustion engines comprisingincombination, a circuit interrupter for controllingan ignition coil, anengine driven camjfor operating the interrupter, and. means- .responsiveto engine combustion chamber pressure .for controlling the angularrelation between .the'interrupter and cam, said meanscomprisinga.cylinder connected with an engine cylinder, a piston in said cylinder,a spring establishing an .alterable predetermined spark advance relationbetween the 'iinterrupter and cam, and -restraim'ng movement of thepiston from .the'spark advancing position to a spark retarding positionuntil the engine cylinder pressure risessubstantially to the point ofdetonation and .means effective .just after detonation tending torestore the predetermined spark advance relation, whereby the ignitionwill be timedto effect engineperformance atcombustion pressures belowthe detonating' point.

2. Ignition apparatus for internal combustion engines comprisingincombination, a circuit interrupter for controlling'an ignition coil, anengine driven cam for operating the interrupter, and means responsive toengine combustion chamber pressure for controlling the angular relationbetween the interrupter and cam, said means comprising a-cylin'derconnected with. an engine cylinder, a piston in said cylinder and aspring restraining movement of thepiston from 1 a spark advancingposition to a spark retarding position until the engine cylinderpressure rises substantially to the point of detonation whereby theignition will be timed to eiiect engineperformancev atcombustionpressures below the detonating point; and mwns for dampingmovements of the piston due tointermittent application of pressures tothe cylinder.

3. Ignition apparatus for internal combustion engines comprising, incombination, a circuit interrupter for controlling, an ignition coil, an

ya, sparkadvancing position to a spark retarding position until theengine cylinder pressure rises substantially to the point of detonationwhereby the ignition will be timed to effect engine performance atcombustion pressures below the detonating pointyand a check valve forcontrolling the passage between the control cylinder and enginecylinder, said check valve having a bleeder passage. 7

4. Ignition apparatus for internal combustion engines comprising, incombination, a circuit interrupter 'for controlling an ignition coil, anengine driven cam for operating the interrupter, and means responsive toengine combustion chamber pressure 'for "controlling the angularrelation between the "interrupter; and" cam, said means comprising acylinder "connected with an engine cylinder, 2, piston in said cylinderand a spring restraining movement or the piston from a spark advancingposition'to aspark retarding position until'the engine cylinder pressurerises substantially to the point of detonation whereby the ignitionwill'be timedto 'effect'engine performance at combustion pressures belowthe detonating'point; and a check valve for'controlling, the passagebetween the control cylinder and the engine cylinder, said valveincluding a'valve disc having a'bleederpassage, and a spring locatedbetween the control piston and valve disc for urging the "disc againstits seat.

5. Ignition apparatus 'for internal "combustion engines "comprising; incombination, a circuit" in terrupter" for controllingan ignition coil,an en gine driven cam for operating the interrupter, means responsive toengine combustion chamber pressure for controlling the. angular relationbetween' the interrupterand cam, saidm-eans comprising a pressureresponsive element, means for communicating thepressure oftheen'gi'ne-cylinderto said element, a spring restraining move-- ment of"said element from a spark advancing position to a'spark retardingpositionuntil'the' engine cylinder pressure rises substantially to thepoint of detonation and meansacoelertzting the return movementof saidelement from a spark retarding posit-ion toward'a spark-advancingposition duringthe-intervalbetween successive'detonations, whereby, theignition will be timed to effectengine performance at-combustionpressures below the 'deton atin'g point.

JOHN B. DYER.

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